If you have experienced YouTube or other similar sites blocking or removing your videos due to music copy right infringement then check this site out : http://incompetech.com/m/c/royalty-free/
Some excellent background tracks of various Genres are offered under Creative Commons license. Maintained by Kevin Macleod and friends this site is a treausre trove for amateur and professional video- editors alike.
I have made this show using one of the number downloaded from the Incompetech site. Images are from the net. This show is for the purpose of introducing Incompetech to my readers only and not for any commercial reasons.